74158-mt----advanced Digital Signal Processing

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Code No: 74158/MT M.Tech. – I Semester Supplementary Examinations, September, 2008 ADVANCED DIGITAL SIGNAL PROCESSING (Electronics & Communications) Time: 3hours

1.a) b) 2.a) b) 3.a)

b) 4.a) b)

Max. Marks:60

Answer any FIVE questions All questions carry equal marks --Briefly explain the applications of DSP in speech coding and in SONAR. Explain different types of methods of signal processing. Define DFT of a sequence x(n). Obtain the relationship between DFT and DTFS. Explain how FFT can be used in computing STFT of a signal x(n). Implement a two-stage decimator for the following specifications: Sampling rate of the input signal = 20 KHz M = 100 Pass band = 0 to 40 Hz Transmission band = 40 to 50 Hz Pass band ripple = 0.01 Stop band ripple = 0.002 Explain the need and application for multirate DSP. Interpret the computation of discrete wavelet transform of a signal x(n) in terms filter banks. Discuss the method for smoothing the periodogram.

5.a) Explain factorization algorithm. b) Determine the Least-square FIR inverse filter of length `3’ for the system with impulse response h(n) given by n=0  1;  h(n) = −α ; n =1  0; otherwise 

1 and the desired response is specified as d(n) = δ(n-2). 2 Also compute the minimum least square error. Contd…2.,

when α =

Code No: 74158/MT

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6.

Explain recursive least square algorithm and determine the equations for the optimum FIR filter co-efficients.

7.

Explain hoe the forward and backward prediction error filters of order `P’ are updated using the weighting factors K pr +1 and K pe +1 to yield the corresponding error filers of order p+1.

8.a) Obtain the relationships between auto correlation and the model parameters. b) Explain spectral estimation based on subspace eigen-analysis. &-&-&-&